Irreversible damage at high levels of potential-induced degradation on photovoltaic modules

Abstract

Potential-induced degradation (PID) of photovoltaic (PV) modules gets a lot of attention since 2010 when Solon published their findings about a degradation mechanism in their PV modules caused by high potential differences between the solar cell and the grounded frame. Module level efficiency drops of 30% and more caused by PID have been reported. A stress test for PID according to IEC 62804 and a recovery test in the same conditions were conducted on a set of 49 commercially available PV modules. In this paper we report the irreversibility of highly affected (i.e. over 85% PID) PV modules. From this point of view, it is important to detect and recover PID before the point of no return. Furthermore, the impact of PID on the different parameters of a PV module and their relevance in order to detect PID in the field are reported.